This is the first in a tremendously innovative series by Jim Butcher. His hero is Harry Blackstone Copperfield Dresden, wizard and private investigator.
I recently re-read it – despite almost never having the time to re-read anything – and enjoyed it just as much this time around. There is something so charming – despite rather graphic descriptions of the damage done to the murder victims – and compelling about a hard-boiled private eye in Chicago who is also a wizard. Butcher catches the hard-boiled tone, adds humor and wizardly mumbo-jumbo, and boils up a detective tale with an ending worthy of any action-adventure movie.
Things I have learned from reading Jim Butcher books: 1) magic is to be treated with respect, and 2) never conjure a demon.
There are about ten books in the series so far, so if this concept appeals to you, you've got a lot of treats in store.